Q. (On prior question 1932, mitzva of standing for the aged) I don’t see it widely practiced in many places, so I’m wondering if there are any heterim for not doing it while learning, davening, bentching, or eating a seuda shel mitzvah,etc? For example, do I need to get up each time during seduat shlishit at shul every time an older man walks by me?
Additionally, some people will raise themselves up a bit in their seat to “sort of” comply with this mitzvah….is that acceptable or advised in a place where standing fully doesn’t appear to be the custom or is it better to always stand fully?
thanks so much . Any differences for Sephardim?
A. Tzitz Eliezer (14: 10) considers if one must stand up when an elder enters in the four amos while one is davening. He concludes that while he is reciting pesukei d’zimra, aleinu, karbanos etc. one must stand. However, while he is reciting Shema he should not stand up. However, many poskim, including the Chida, Rav Yosef Chaim Zonnenfeld zt”l, and the Chazon Ish, all maintain that one should stand before the elderly even while reciting Shema. See also Mevakshei Torah, (v. 4, p. 250) and Ishei Yisroel (p. 204 n. 85)
In the following cases the mitzvah of mipnei seiva takum, which requires one to rise to his full height, may not apply. Instead, the mitzvah is merely to show some measure of respect, such as rising slightly from one’s seat:
If one is an employee and standing up will require wasting his employer’s time. (Y.D. 244: 5).
If the “younger” person is also over seventy. (Y.D. 244: 8).
If the younger person is a greater talmid chacham than the older person.(Y.D. 244: 7).
If the older person specifically forgoes the honor that is due to him. (see next question)
If one is ill, or an Avel during shivah. (Rema Y.D. 376: 1. On Tishah BeAv, this mitzvah does not apply, (R” Akiva Eiger, ibid, quoting Shevus Yaakov).
As mentioned above, if one is in the middle of davening and standing will disturb his kavanah.
Horav Shlomo Miller’s Shlit’a opinion is that in our days, due to the fact that people live longer lives, reaching the age of seventy is common and does not seem to be a major achievement anymore. Therefore, septuagenarians mostly do not expect nowadays any recognition and on the contrary, they may be even upset that one should consider them old.
The Rov advises that one should follow the minhag hamakom and behavior of the location he is on, and act accordingly. If in doubt, he should consult with a competent local authority.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a